Wear property of plasma spray coating in Cr2O3/TiO2 powder manufactured of spray dry method on the aluminum substrate was inspected for the application of piston-ring of automotive engine. The plasma spray coatings were varied with feed rate and particle size. Using the ball-on disc type tribometer, wear volume property and surface roughness were investigated. The delamination of the coating layers and wear track were observed with SEM. Also, the cross-section of wear track were investigated, using optical microscopy. As a result of experiment, wear mechanism was addressed.